1. Field of the Invention
The present invention relates to a KVM switch which is connected between a computer and peripheral devices such as a mouse, a keyboard, and a monitor, as well as a method for controlling the same, a switching system for multi-monitor, and a switching method for multi-monitor.
2. Description of the Related Art
Conventionally, there has been known a KVM (K:keyboard, V:video, M:mouse) switch including a terminal emulator which is connected between a plurality of servers and peripheral devices such as a mouse, a keyboard, and a monitor (see U.S. Pat. No. 6,567,869).
The KVM switch converts communication data output from a communication port (e.g. a serial port, a USB (Universal Serial Bus) port, or the like) of selected server into analog video data, and outputs the analog video data to the monitor. That is, the KVM switch can switch the communication data output from one of the plurality of servers to communication data output from another server, and display the switched communication data as an analog image on the monitor.
When the KVM switch is used, video outputs from the plurality of servers are switched, and hence a user cannot watch the pieces of video data together.
Conventionally, there has been known a KVM switch which is connected to a plurality of servers and peripheral devices such as the mouse, the keyboard, and the monitor, and is connected to a client which is a remote terminal via a network (See e.g. Rose. Electronics Ltd., product name “UltraMatrix Remote” http://www.rose.com/htm/ultramatrixremote.htm))
Further, conventionally, there has been known a system including a switching mechanism 34 which is provided between a plurality of compute resource units 14 and a plurality of visualization resource units 16, and interconnects between them (see Japanese Laid-Open Patent Publication No. 2004-5449).
Conventionally, there has been known a system including a server, a client, and a KVM switch connecting the server and the client to each other via a network (See e.g. Hewlett-Packard Ltd., HP Blade Workstation solution, Composition/operation image (http://h50146.www5.hp.com/products/workstations/blade_ws)).
However, the KVM switches in U.S. Pat. No. 6,567,869, and Rose Electronics Ltd. do not adapt to a multi-monitor function. That is, there is no KVM switch which can smoothly switch a plurality of video outputs output from each server, and outputs the plurality of video outputs to the remote terminal. In each of the compute resource units 14 in Japanese Laid-Open Patent Publication No. 2004-5449, and the server in Hewlett-Packard Ltd., the output of the video signal is only one, and hence they do not adapt to the plurality of video outputs.
Also, in the system of Rose Electronics Ltd., the signals of the keyboard, the mouse, and the video are brought together in the server, and compression processing is done to the signals. Therefore, a load is applied to the server.